Patent Document 1 discloses a conventional overturn preventing device. This overturn preventing device is mounted between a top surface of a piece of furniture installed on a floor and a ceiling. The overturn preventing device includes a support pillar with a built-in spring and setting members attached to both ends of the support pillar respectively. Each setting member includes a disk-shaped setting part body and a columnar shaft vertically extending from a center of one side surface of the setting part body. The shafts of the setting members are inserted into both ends of the support pillar respectively, and at least one of the shafts is disposed to be axially movable forward and backward. The spring applies an elastic force to each setting member which is movable forward and backward in a lengthwise direction of the overturn preventing device. While the spring is slightly compressed, the setting part body of one setting member is caused to abut against the top surface of the furniture and the setting part body of the other setting member is caused to abut against the ceiling. Thus, the overturn preventing device is mounted between the top surface of the furniture and the ceiling with an axis line extending in a vertical direction, thereby preventing the furniture from being overturned due to quakes of earthquake or the like.